Lighthouse

Lighthouse is an open-source, automated tool for improving the performance, quality, and correctness of your web apps.
When auditing a page, Lighthouse runs a barrage of tests against the page, and then generates a report on how well the page did. From here you can use the failing tests as indicators on what you can do to improve your app.
* Quick-start guide on using Lighthouse:
https://developers.google.com/web/tools/lighthouse/
* View and share reports online:
https://googlechrome.github.io/lighthouse/viewer/
* Github source and details:
https://github.com/GoogleChrome/lighthouse